When producing synthetic leather, polyurethane and polyvinyl chloride have been mainly used as typical coating materials.
However, these polyurethane and/or polyvinyl chloride based synthetic leathers have environmental concerns. Polyurethane based product uses organic solvent such as DMF (dimethylformamide) or MEK (methyl ethyl ketone) during the production process, and traces of these solvents/DMF are remained in the final product. It also has performance concerns from temperature variations which causes flexibility issues, and from hydrolysis degradation absorbing moisture from the atmosphere. Accordingly, technologies of using a water-dispersible polyurethane, not containing organic solvent, have been developing, but there are difficulties in the processing, and hydrolysis degradation issue still remains.
Korean Patent Application Laid-Open No. 2003-0095872 discloses a method for producing synthetic leather using a liquid silicone rubber. But synthetic leather produced by this method has failed to satisfy the strict physical properties requirements such as flame retardancy or smoke density for an interior material of an aircraft or a ship, and has also failed to satisfy the adhesion strength required for products.
Korean Patent No. 1,381,914 discloses a method for producing synthetic leather using liquid silicone rubbers having different characteristics. However, the synthetic leather produced by this method has poor adhesion properties to the supporting backing cloth, and the surface durability of the product is not strong enough for heavy duty commercial applications, so there happened quality issues when processing the product to make commercial upholstery and in the actual use of the product in the field.